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Index › Programming Questions & Help › Syntax Questions › Sort list by length

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Sort list by length (Read 1149 times)

clankill3r Full Member Offline Posts: 210 Netherlands	Sort list by length Oct 29^th, 2009, 6:07am How can i sort a list by length? So this Quote: such like should so through Will get like: Quote: through should such like so

blindfish God Member Offline Posts: 793	Re: Sort list by length Reply #1 - Oct 29^th, 2009, 6:32am Assuming you haven't found anything suitable in the Reference then I suspect you'll need to rely on Java for that. This ,%20java.util.Comparator)]Array sort method allows you to pass a Comparator as an argument. This would be a method that took two string lengths and returned an appropriate argument to the sort method.
	Where is the what if the what is in why?

PhiLho

Re: Sort list by length
Reply #2 - Oct 29^th, 2009, 6:38am

Details depend on the exact nature of your list. Array? ArrayList? Something else?

But basically, you have to sort using a Comparator class (or if you define your own class, you can make it to implement Comparable, but that's not the point here).

Here is an example:
Code:

class CompareStringLength implements Comparator
{
  int compare(Object o1, Object o2)
  {
    String s1 = (String) o1;
    String s2 = (String) o2;
    return s1.length() - s2.length();
  }
}

String[] words =
{
  "Processing",
  "is",
  "an",
  "awesome",
  "software",
  "isn't",
  "it?"
};

println(words);
Arrays.sort(words, new CompareStringLength());
println(words);

Just invert s1 and s2 in the return clause to sort in the reverse order.

toxi

Re: Sort list by length
Reply #3 - Oct 29^th, 2009, 6:41am

One easy way to do this would be with the Java Collections API and a custom Comparator:

Code:

void setup() {
  ArrayList words=new ArrayList();
  words.add("processing");
  words.add("hi");
  words.add("shuffle");
  words.add("world");
  Collections.sort(words,new LengthComparator());
  for(Iterator i=words.iterator(); i.hasNext();) {
    println(i.next());
  }
}

class LengthComparator implements Comparator {
  public int compare(Object a, Object b) {
    String sa=(String)a;
    String sb=(String)b;
    return sb.length()-sa.length();
  }
}

Using such comparators you can sort any type of object based on one or more properties...

postspectacular.com | toxi.co.uk

toxi Full Member Offline Posts: 203	Re: Sort list by length Reply #4 - Oct 29^th, 2009, 6:42am 3 people = same idea
	postspectacular.com \| toxi.co.uk

clankill3r Full Member Offline Posts: 210 Netherlands	Re: Sort list by length Reply #5 - Oct 29^th, 2009, 6:49am damnit, difficult. The list is a String[]; The input is from a text file: String [] eng; eng = loadStrings("1000_eng.txt"); if someone could give an example with that then that would be really nice.

toxi Full Member Offline Posts: 203	Re: Sort list by length Reply #6 - Oct 29^th, 2009, 7:07am But it's exactly the same as we've written above. loadStrings() returns an array of Strings, so then just do this: Code: void setup() { String [] eng; eng = loadStrings("1000_eng.txt"); Arrays.sort(eng, new LengthComparator()); println(eng); } (using the LengthComparator class from my reply above)
	postspectacular.com \| toxi.co.uk

clankill3r Full Member Offline Posts: 210 Netherlands	Re: Sort list by length Reply #7 - Oct 29^th, 2009, 7:53am thank you all so much, specially for the short time.

PhiLho

Re: Sort list by length
Reply #8 - Oct 29^th, 2009, 8:58am

toxi wrote on Oct 29^th, 2009, 6:42am:

3 people = same idea

Yes, in order of time spent on writing the answer... and testing the given sample! Grin

clankill3r wrote on Oct 29^th, 2009, 6:49am:

The list is a String[];

My sample used that...
That's the nice thing with having multiple answers: they addressed slightly different domains.

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